Answer: 0.5 seconds or 2.625 seconds
Explanation:
At t = 0, The ball is 4 ft above the ground.
The height of the football varies with time in the following way:
s(t) = -16 t² + 50 t + 4
we need to find the time in which the height would of the football would be 25 ft:
⇒25 = -16 t² + 50 t + 4
we need to solve the quadratic equation:
⇒ 16 t² - 50 t + 21 = 0
⇒ t = 0.5 s or 2.625 s
Therefore, at t = 0.5 s or 2.625 s, the football would be 25 ft above the ground.
Answer:
Explanation:
Not enough information.
IF we ASSUME she wants the car to be at LAUNCH LEVEL after 1 second of flight.
THEN
The highest point will have zero vertical velocity and will have taken ½ second to get there. This means that the initial vertical velocity was
v = gt
vy₀ = 9.8(0.5)
vy₀ = 4.9 m/s
vsinθ = vy₀
v = vy₀/sinθ
v = 4.9/sin32
v = 9.2466...
v = 9.2 m/s
Here is your answer
b) 
REASON :
We know that
Velocity= Frequency× Wavelength
So,
Frequency= Velocity/wavelength
Here,
V= 3× 10^8 m/s
Wavelength= 2×10^-3 m
Hence,
Frequency= 3×10^8/2×10^-3
= 3/2 × 10^11
= 1.5× 10^11 Hz
HOPE IT IS USEFUL
Given:
The initial velocity of the object, v=30 m/s
a_t=0
a_c≠0
The time period is Δt.
To find:
The right conclusion among the given choices.
Explanation:
a_t represents the tangential accleration on the object and a_c represents the centripetal acceleration on the object.
The centripetal acceleration is the acceleration that keeps the object in its circular path. The centripetal force only changes the direction of the velocity and not the magnitude.
Thus the magnitude of the velocity of the object remains the same after a time interval of Δt. But the direction of the velocity of the object will be changed and will be unknown after Δt seconds.
Final answer:
Thus the object will be traveling at 30 m/s in some unknown direction.
Therefore, the correct answer is option a.
Answer:
(c) position
Explanation:
From the work-energy theorem, the workdone by a force on a body causes a change in kinetic energy of the body.
But, remember that the work done (W) by a force (F) on a body is the product of the force and the distance d, moved by the body caused by the force. i.e
W = F x d
This distance is a measure of the position of the body at a given instance.
Therefore, the work done is given by the force as a function of distance (or position).
