Answer:
The magnitude of change in momentum is (2mv).
Explanation:
The momentum of an object is given by the product of mass and velocity with which it is moving.
Let the mass of ball is m. A tennis player smashes a ball of mass m horizontally at a vertical wall. The ball rebounds at the same speed v with which it struck the wall.
Initial speed of the ball is v and final speed, when it rebounds, is (-v). The change in momentum is given by :
p = final momentum - initial momentum
So, the magnitude of change in momentum is (2mv).
Given : A ball of mass 40 g moving at a velocity of 4 m/s.
To find : Calculate the kinetic energy in joules ?
Solution :
The kinetic energy formula is given by,
where, v is the velocity v=4 m/s
m is the mass m=40 g
Convert g into kg,
Substitute the values,
Therefore, the kinetic energy is 0.32 Joules.
It doesn't the sun stays still we move around the sun
Answer:
Explanation:
In the first case you can use the expression for the Doppler effect when the source is getting closer and getting away
( 1 )
( 2 )
f' = perceived frequency when the source is getting closer
f'' = perceived frequency when the source is getting away
f = source frequency
v = relative speed
vs = sound speed
by dividing (1) and (2) you have
but this is the relative velocity, you have that
a. hence, the speed of the police car is 102.5m/s
The work needed if a force of 3N is used to move a table 25 metres is 75Nm (joules).
<h3>How to calculate work done?</h3>
Work is a measure of energy expended in moving an object. This means that no work is done if the object does not move.
Force is a physical quantity that denotes the ability to push, pull, twist or accelerate a body and which has a direction and is measured in Newtons.
Work done on an object can be calculated by multiplying the force applied to move the object by the distance the object moves as follows:
Work done = Force (N) × distance (m)
According to this question, a force of 3 Newtons is used to move a table over a distance of 25 meters. The work done on the table can be calculated as follows;
W = 3N × 25metres
W = 75Nm
Therefore, 75Nm is the work done on the table.
Learn more about work done at: brainly.com/question/2117638
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