Answer:
75 m/s
Explanation:
We can apply motion equations here
V = U + a * t
V = velocity @ t time
U = initial velocity
a = acceleration
t = time taken
V = U + a * t
V = 0+ 3 * 25
V = 75 m/s
After 25 seconds , subjected to the given acceleration velocity is increased from 0 to 75 m/s
<span>1) at rest his
weight is 840 N
=> 840N = mass * g => mass = 840 N / g = 840 N / 9.8 m/s^2 = 85.7 kg
2) as the elevator rises, his weight increases to 1050 N,
The reading of the scale is the norma force of it over the body of the person.
And the equation for the force is: Net force = mass * acceleration = normal force - weight at rest
=> mass * acceleration = 1050 N - 840 N = 210 N
acceleration = 210 N / mass = 210 N / 85.7 kg = 2.45 m/s^2 (upward)
3) when the elevator slows to a stop at the 10th
floor, his weight drops to 588 N
=> mass * acceleration = 588 N - 840 N = - 252 N
=> acceleration = - 252 N / 85.71 kg = - 2.94 m / s^2 (downward)
Answer:
Acceleration at the beginning of the trip 2.45 m/s^2 upward
Acceleration at the end of the trip 2.94 m/s^2 downward
</span>
Answer:
A black hole is a region of space having a gravitational field so intense that no matter or radiation can escape.
Explanation:
Sorry if this isn't what you meant or were looking for.
Answer:
14 rev
Explanation:
= initial angular velocity = 2.5 revs⁻¹
= final angular velocity = 0.8 revs⁻¹
= Angular acceleration = - 0.2 revs⁻²
= Angular displacement
Using the equation
So the number of revolutions are 14
Answer:
v = 7.4 m/s
Explanation:
Given that,
Mass if a volleyball, m = 5 kg
The ball reaches a height of 2.8 m
We need to find how fast the ball is going as it bumped into the air. Ket the velocity is v. Using the conservation of energy to find it as follows :
So, the required speed is 7.4 m/s. Hence, the correct option is (b).
