Physics Kinematics Level: High School
Explain how a positive acceleration could produce a deceleration .An object which was moving in the negative direction would slow down , if its acceleration were positive (a negative acceleration would mean the velocity was getting more negative ).
An object which was moving in the positive direction would slow down if its acceleration were negative (a negative acceleration would mean the velocity was getting more negative .)
Physics Kinematics Level: High School
A ball is released moving straing up at 15 m/s . A short time late it is falling downward at 15 m/s . What was the magnitude of its average speed over the time period ?30 m/s
15 m/s
0 m/s
7.5 m/s
Average speed = (u+v)/2 (We are considering the magnitude.)
Physics Kinematics Level: High School
Can an object have increasing speed while its acceleration is decreasing ?a) Yes , any non-zero acceleration in the same as the motion of the object will be increasing its speed .
b) No , because if acceleration is decreasing the object will be slowing down
c) No , this is impossible because of the way in which acceleration is defined .
d) Yes , and an example would be an object falling in the absence of air friction .
Physics Kinematics Level: High School
Barbara travels 20 km Northward , then travels 40 km Eastward, then continues for 50 km in a Southward direction. What displacement will now take her back to her initial position ?50 km Northwest.
30 km Westward + 40 km Northward
30 km Eastward + 40 km Southward
40 km Eastward + 30 km Southward
40 km Westward + 30 km Northward
30 km Northward + 30 km Westward
(Displacement is the shortest path , so it will be a single distance )
Physics Kinematics Level: High School
A ball is thrown straight up with a speed of 36 m/s . How long does it take to return to its starting point ?7.3 s
5.3 s
Physics Kinematics Level: High School
A car starts from rest and accelerates to a speed of 72 km/h in 5 seconds . Assuming uniform acceleration . What is the acceleration in meters per second squared ?0.1 m/s^2
360 m/s^2
14.4 m/s^2
4 m/s^2
Physics Vectors Level: High School
All of the following are vectors , except .Displacement .
Density .
Force .
Velocity .
Physics Work,Power & Energy Level: High School
A gun is fired vertically into a 2.40 kg block of wood at rest directly above it . If the bullet has a mass of 22.0 g and a speed of 340 m/s . how high will the block rise into the air ?
Physics Force & Laws Of Motion Level: High School
A 140 kg tackler moving at 3.0 m/s meets head on (and tackles) a 90 kg halfback moving at 6.5 m/s . What will be their mutual speed immediately after the collision ?
Physics Force & Laws Of Motion Level: High School
A 15000 kg railraod car travels alone on a level frictionless track with a constant speed of 18.0 m/s . A 5000 kg additional load is dropped onto the car . What then will be its speed ?
Physics Force & Laws Of Motion Level: High School
Conservation of linear momentum
A child throws a 3.40 kg package horizontally from a boat with a speed of 10.0 m/s . Calculate the resulting velocity of the boat , assuming it was initially at rest . The mass of the child is 20.0 kg and that of the boat is 60.0 kg .
Physics Force & Laws Of Motion Level: High School
Calculate the force exerted on a rocket , given that the propelling gases are expelled at a rate of 1000 kg/s with a speed of 60000 m/s ( at takeoff )
Physics Gravitation Level: High School
A block whose weight is 34.0 N rests on a horizontal table . A horizontal force of 48 N is applied to the block . The coefficient of static and kinetic friction are 0.650 and 0.420 N , respectively . Will the block move under the influence of the force , and , if so , what will be the blocks acceleration ? (If not enter 0)
Physics Gravitation Level: High School
Three particles are far away from any other objects and located on a straight line . The masses of these particles are mA = 363 kg , mB = 517 kg, mC = 154 kg . Find the magnitude and direction of the net gravitational force acting on each of three particles (let the direction to the right be positive )
Physics Kinematics Level: High School
An arrow starting from rest , leaves the bow with a speed of 15.0 m/s . If the average force exerted on the arrow by the bow were doubled . all else remaining the same , with what speed would the arrow leave the bow ?