Motion and Forces
The variation of the displacement of an object with time is shown on a graph. What does the area under the graph represent?
No Physical Quantity
speed
What is rate of distance traveled along a path
What is the work done if a force of 50N is applied on an object and moves the object fully around a circular track of radius 5m?
0J
A 1000 kg car accidentally drops from a crane and crashes at 30 m.s-1 onto an unfortunate student below. What impulse acts on the car when it hits the student?
30000 kg*m/s
High number of significant figures and a small spread of results. Accurate or Precise
Precise
The acceleration of free fall of a small sphere of mass 0.005kg when close to the surface of Jupiter is 25m/s^2. The gravitational field strength at the surface of Jupiter is...
A. 0.0002N/kg
B. 0.13N/kg
C. 25N/kg
D. 5000N/kg
C. 25N/kg
acceleration
What is rate of change of velocity with time
The initial kinetic energy of a block moving on a horizontal floor is 48 J. A constant frictional force acts on the block bringing it to rest over a distance of 2 m. What is the frictional force on the block?
24N
If a force of 300N is exerted upon a 60 kg mass for 4 seconds, how much impulse does the mass experience?
300 x 4 = 1200N.s
How many significant figures are there in the number 0.0450
3
An object is projected vertically upwards at time t = 0. Air resistance is negligible. The object passes the same point above its starting position at times 2 s and 8 s.
If g = 10 m s–2, what is the initial speed of the object?
50m/s
Impulse
rate of change in momentum
A student of weight 600N climbs a vertical ladder 6.0m tall in a time of 8.0s. What is the power developed by the student against gravity?
450W
A 200 g mass is attached to a spring of spring constant k. The spring is compressed 15cm from its equilibrium value. When released the mass reaches a speed 5 m/s. What is the spring constant(N/m)?
m = 200 g = 0.2 kg; Δx = 15 cm = 0.15 m; v = 5 m/s; k = ?
220N/m
Which of the following is a scalar quantity?
A. Velocity
B. Momentum
C. Kinetic energy
D. Acceleration
C
A parachutist of total mass 70 kg is falling vertically through the air at a constant speed of 8m.s–1.
What is the total upward force acting on the parachutist?
700N
Newton's First Law
What is a body will remain at constant velocity unless a net force acts on it
An object of mass 2kg is thrown vertically downwards with an initial kinetic energy of 100J. What is the distance fallen by the object at the instant when its kinetic energy has doubled?
5.0m
A rocket is fired vertically. At its highest point, it explodes. What happens to its total momentum and total kinetic energy as a result of the explosion?
Momentum unchanged, Kinetic energy increased
A stone falls from rest to the bottom of a water well of depth d. The time t taken to fall is 2.0 ±0.2 s. The depth of the well is calculated to be 20 m using d = 0.5*at². The uncertainty in a is negligible.
What is the absolute uncertainty in d?
A. ± 0.2 m
B. ± 1 m
C. ± 2 m
D. ± 4 m
D. ± 4 m
projectile is fired horizontally from the top of a cliff. The projectile hits the ground 4 s later at a distance of 2 km from the base of the cliff. What is the height of the cliff?
80m
Elastic Collision
What is a collision in which kinetic energy is conserved
A student makes three statements about situations in which no work is done on an object.
I. The object is moving with uniform circular motion.
II. A force is applied to the object in the direction of its velocity.
III. A force is applied to the object in a direction opposite to its motion.
Which ones are correct?
I only
Sean (mass 80 kg) fires a 510g bullet from a shotgun. His shotgun has a mass of 5 kg. The muzzle velocity is 347 m/s With what velocity does Sean (and his gun) recoil?
2.08m/s
Which is a unit of force?
A. J m
B. J m–1
C. J m s–1
D. J m–1 s
B. J m–1