Answer:



Explanation:
= Torque = 36.5 Nm
= Initial angular velocity = 0
= Final angular velocity = 10.3 rad/s
t = Time = 6.1 s
I = Moment of inertia
From the kinematic equations of linear motion we have

Torque is given by

The wheel's moment of inertia is 
t = 60.6 s
= 10.3 rad/s
= 0

Frictional torque is given by

The magnitude of the torque caused by friction is 
Speeding up

Slowing down

Total number of revolutions


The total number of revolutions the wheel goes through is
.
Answer:
8977.7 kg/m^3
Explanation:
Volume of water displaced = 55 cm^3 = 55 x 10^-6 m^3
Reading of balance when block is immersed in water = 4.3 N
According to the Archimedes principle, when a body is immersed n a liquid partly or wholly, then there is a loss in the weight of body which is called upthrust or buoyant force. this buoyant force is equal to the weight of liquid displaced by the body.
Buoyant force = weight of the water displaced by the block
Buoyant force = Volume of water displaced x density of water x g
= 55 x 10^-6 x 1000 x .8 = 0.539 N
True weight of the body = Weight of body in water + buoyant force
m g = 4.3 + 0.539 = 4.839
m = 0.4937 kg
Density of block = mass of block / volume of block
= 
Density of block = 8977.7 kg/m^3
Answer:
The measured redshift is z =2
Explanation:
Since the object is traveling near light speed, since v/c = 0.8, then we have to use a redshift formula for relativistic speeds.

Finding the redshift.
We can prepare the formula by dividing by lightspeed inside the square root to both numerator and denominator to get

Replacing the given information


Thus the measured redshift is z = 2.
Answer:
∆PE = 749.7 J
At 0.9 m high, PE = 793.8 J
At 1.75 m high, PE = 1543.5 J
Answer: the wall contracts the force exerted by his head. The wall produces the opposite force which is equal to the force his head bangs the wall with.
Explanation: if his head exerts a much greater force than the wall can counteract the wall will be destroyed, if the wall exerts a much greater force than his head exerts he will be pushed far back and might even suffer a broken head.
The wall in this case provides the opposite reactive force.