Hello there.
What does an Electric Motor do?
Answer: Converts electrical energy into mechanical energy.
Answer:
A.) r = 2t
B.) V = 33.5t^3
Explanation:
Given that a spherical balloon is being inflated and the radius of the balloon is increasing at a rate of 2 cm/s
A) Express the radius (r) of the balloon as a function of the time (t).
Since the rate = 2 cm/s that is,
Rate = radius/ time
Therefore,
2 = r/t
Make r the subject of formula
r = 2t
(B) If V is the volume of the balloon as a function of the radius, find V or and interpret it.
Let assume that the balloon is spherical. Volume of a sphere is;
V = 4/3πr^3
Substitute r = 2t into the formula
V = 4/3π(2t)^3
V = 4/3π × 8t^3
V = 32/3 × πt^3
V = 33.5t^3
30km. 24 the first two hours and 6 the half hour
Answer:
Part a)

Part b)

Part c)
Speed is more than the required speed so it will reach the top
Explanation:
Part a)
As we know that there is no frictional force while block is moving on horizontal plane
so we can use energy conservation on the block



Part b)
If the track has average frictional force of 7 N then work done by friction while block slides up is given as



work done against gravity is given as



Now by work energy equation we have



Part c)
now minimum speed required at the top is such that the normal force must be zero



so here we got speed more than the required speed so it will reach the top
At the ground the ball will always have velocity along the direction of gravity. If upward motion is taken positive it will always have negative velocity at the ground because, if the ball was given an initial upward velocity then gravity will decelerate it and bring it down with a negative final velocity. If the ball is given an initial downward velocity then the ball will be further accelerated by gravity in the downward direction only, again maintaining negative direction. The magnitude however in both cases will be different. the final velocity at the ground will have higher magnitude in case of elevator moving downwards.