Answer:
pi / 2 radians / s
Explanation:
One revolution = 2 pi Radians in 4 seconds
2 pi / 4 = pi/2 radians / s
Answer:
The magnetic flux through the desk surface is
.
Explanation:
Given that,
Magnetic field B = 0.42 T
Angle =68°
We need to calculate the magnetic flux

Where, B = magnetic field
A = area
Put the value into the formula



Hence, The magnetic flux through the desk surface is
.
Answer:
-2200 N
Explanation:
The change in momentum of Sarah is equal to the impulse, which is the product between the force exerted by the seatbelt on Sarah and the time during which the force is applied:
where
m is the mass
is the change in velocity
F is the average force
is the duration of the collision
In this problem:, we have:
m = 55 kg is Sarah's mass
is the change in velocity
is the duration of the collision
Solving for F, we find the force exerted by the seatbelt on Sarah:
Where the negative sign indicates that the direction of the force is opposite to that of Sarah's initial velocity.
Answer:
-1500 m/s2
Explanation:
So the ball velocity changes from 10m/s into the wall to -8m/s in a totally opposite direction within a time span of 0.012s. Then we can calculate the average acceleration of the ball as the change in velocity over a unit of time.

A). Both the energy and the wave travel in the same direction.
If they didn't, they'd wind up in different cities almost instantly.