Answer :
(a) The initial velocity is, 14.8 m/s
(b) The acceleration is, 
Explanation :
By the 1st equation of motion,
...........(1)
where,
v = final velocity = 0 s
u = initial velocity
t = time = 6.35 s
a = acceleration
The equation 1 will be:
..........(2)
By the 2nd equation of motion,
...........(3)
where,
s = distance = 47 m
Now substitute equation 2 in 3, we get:
By solving the term, we get:
The acceleration is,
Now we have to calculate the initial velocity.
Using equation 2, we gte:
The initial velocity is, 14.8 m/s
Answer:
imma try nd help cuz i havent seen anybody answer so
1.sara
2.same for both
3.tom
Explanation:
Answer:
v = 11 m/s is her final speed
Explanation:
work done by gravity = m g Δh = 40×9.8×10 = 3920 Joules
Work done by friction = - force×distance = - 20×100 = - 2000 Joules
[minus sign because friction force is opposite to the direction of motion]
Initial K.E. = (1/2) m u^2 = (1/2) × 40 × 5^2 = 500 Joules
Now, by work energy theorem
Work done = change in kinetic energy.
Final K.E. = initial K.E. + total work = 500 + 3920 - 2000 = 2420 Joules
Now, Final K.E. = (1/2) m v^2 [final speed being v= speed at the bottom]
⇒ 2420 = (1/2)×40×v^2
⇒ 121 = v^ 2
v = 11 m/s is her final speed
Answer:
that is the first law of motion or newtons first law of motion
