Physics

# Problems

PhysicsProblems

## 5.1Vector Addition and Subtraction: Graphical Methods

25 .
A person attempts to cross a river in a straight line by navigating a boat at $15\,\text{m/s}$. If the river flows at $5.0\,\text{m/s}$ from his left to right, what would be the magnitude of the boat’s resultant velocity? In what direction would the boat go, relative to the straight line across it?
1. The resultant velocity of the boat will be $10.0\,\text{m/s}$. The boat will go toward his right at an angle of $26.6^\circ\!$ to a line drawn across the river.
2. The resultant velocity of the boat will be $10.0\,\text{m/s}$. The boat will go toward his left at an angle of $26.6^\circ\!$ to a line drawn across the river.
3. The resultant velocity of the boat will be $15.8\,\text{m/s}$. The boat will go toward his right at an angle of $18.4^\circ\!$ to a line drawn across the river.
4. The resultant velocity of the boat will be $15.8\,\text{m/s}$. The boat will go toward his left at an angle of $18.4^\circ\!$ to a line drawn across the river.
26 .
A river flows in a direction from south west to north east at a velocity of $7.1\,\text{m/s}$. A boat captain wants to cross this river to reach a point on the opposite shore due east of the boat’s current position. The boat moves at $13\,\text{m/s}$. Which direction should it head towards if the resultant velocity is $19.74\,\text{m/s}$?
1. It should head in a direction $22.6^\circ\!$ east of south.
2. It should head in a direction $22.6^\circ\!$ south of east.
3. It should head in a direction $45.0^\circ\!$ east of south.
4. It should head in a direction $45.0^\circ$ south of east.

## 5.2Vector Addition and Subtraction: Analytical Methods

27.

A person walks 10.0 m north and then 2.00 m east. Solving analytically, what is the resultant displacement of the person?

1. $R→R→$ = 10.2 m, θ = 78.7º east of north
2. $R→R→$ = 10.2 m, θ = 78.7º north of east
3. $R→R→$ = 12.0 m, θ = 78.7º east of north
4. $R→R→$ = 12.0 m, θ = 78.7º north of east
28 .
A person walks $12.0^\circ\!$ north of west for $55.0\,\text{m}$ and $63.0^\circ\!$ south of west for $25.0\,\text{m}$. What is the magnitude of his displacement? Solve analytically.
1. $10.84\,\text{m}$
2. $65.1\,\text{m}$
3. $66.04\,\text{m}$
4. $80.00\,\text{m}$

## 5.3Projectile Motion

29 .
A water balloon cannon is fired at $30\,\text{m/s}$ at an angle of $50^\circ\!$ above the horizontal. How far away will it fall?
1. $2.35\,\text{m}$
2. $3.01\,\text{m}$
3. $70.35\,\text{m}$
4. $90.44\,\text{m}$
30.

A person wants to fire a water balloon cannon such that it hits a target 100 m away. If the cannon can only be launched at 45° above the horizontal, what should be the initial speed at which it is launched?

1. 31.3 m/s
2. 37.2 m/s
3. 980.0 m/s
4. 1,385.9 m/s

## 5.4Inclined Planes

31 .
A coin is sliding down an inclined plane at constant velocity. If the angle of the plane is $10^\circ\!$ to the horizontal, what is the coefficient of kinetic friction?
1. $\mu_\text{k} = 0$
2. $\mu_\text{k} = 0.18$
3. $\mu_\text{k} = 5.88$
4. $\mu_\text{k} = \infty$
32.

A skier with a mass of 55 kg is skiing down a snowy slope that has an incline of 30°. Find the coefficient of kinetic friction for the skier if friction is known to be 25 N .

1. $μk = 0 μk = 0$
2. $μk = 0.05 μk = 0.05$
3. $μk = 0.09 μk = 0.09$
4. $μk = ∞ μk = ∞$

## 5.5Simple Harmonic Motion

33 .
What is the time period of a $6\,\text{cm}$ long pendulum on earth?
1. $0.08\,\text{s}$
2. $0.49\,\text{s}$
3. $4.9\,\text{s}$
4. $80\,\text{s}$
34 .
A simple harmonic oscillator has time period $4\,\text{s}$. If the mass of the system is $2\,\text{kg}$, what is the force constant of the spring used?
1. $0.125\,\text{N/m}$
2. $0.202\,\text{N/m}$
3. $0.81\,\text{N/m}$
4. $4.93\,\text{N/m}$
Order a print copy

As an Amazon Associate we earn from qualifying purchases.