Suvat
What is the horizontal acceleration of a projectile during its flight?
zero
What does the area under a velocity-time graph represent?
Displacement)
Archimedes' Principle states that a body partially or fully submerged in a fluid experiences an upward force equal to the ______ of the fluid displaced.
Weight
Define "work done" in terms of force and displacement.
W=Fdcosθ
Define momentum in terms of mass and velocity.
p=mv
A ball is thrown horizontally at 20 m/s from a height of 45 m. How long does it take to hit the ground?
almost 3 seconds
On a displacement-time graph, what does the slope represent?
Velocity
What is the unit of strain?
No unit!
What is the unit of power in the SI system?
Watt or W\text{W}W
State the principle of conservation of momentum.
The total momentum of a closed system remains constant, provided no external forces act on it
If an object starts at rest and accelerates uniformly at 5 m/s² for 4 seconds, what is its final velocity?
20 m/s
If the velocity-time graph is a straight horizontal line, what can you say about the motion of the object?
The object is moving at a constant velocity.
If a 10 kg object experiences a net force of 50 N, what is its acceleration?
5 m/s2
An engine transfers 500 J of energy in 10 seconds. What is its power output?
50 W
A 2 kg ball moving at 3 m/s collides elastically with a stationary 3 kg ball. What is the total momentum after the collision?
6 kg·m/s, the same as before the collision.
A projectile is launched at 30° with an initial velocity of 50 m/s. Calculate its maximum height.
31.9m
If the area under a velocity-time graph is 50 m and the object started at 0 m, where will it be after that time?
50 m
A wire of length 2 m and cross-sectional area 0.01 m² is stretched by a force of 200 N. Calculate the stress.
σ=F/A=200/0.01=20,000Pa
Calculate the work done when a 100 N force moves an object 5 m at an angle of 60° to the displacement.
W=100⋅5⋅cos60∘=250J
In an inelastic collision, what happens to the kinetic energy of the system?
Some of the kinetic energy is converted into other forms, like heat or sound.
An object accelerates uniformly at 2 m/s² for 6 seconds, reaching a final velocity of 20 m/s. What was its initial velocity?
8m/s.
Sketch a velocity-time graph for an object undergoing constant acceleration and describe its key features.
A straight line with a positive slope passing through the origin
A uniform beam of length 4 m and weight 40 N is supported at its center. A 30 N force is applied 1 m from the left end, and a 20 N force is applied 1.5 m from the left end. What is the distance from the left end to the point where the support force must act to keep the beam in equilibrium?
2.5meters
An object of mass 10 kg is lifted vertically through a height of 2 m. What is the work done against gravity?
W=mgh=10⋅9.8⋅2=196J
A 2 kg ball moving at 5 m/s collides elastically with a stationary 3 kg ball. After the collision, the 2 kg ball moves at 2 m/s in the opposite direction. What is the velocity of the 3 kg ball after the collision?
4.67 m/s