Answer:

Explanation:
Potential Energy= Kinetic Energy
Let
be the value of Kinetic Energy.
We know that

Make
the subject of the formula to get speed at the bottom of the hill.

Answer:
L= 1 m, ΔL = 0.0074 m
Explanation:
A clock is a simple pendulum with angular velocity
w = √ g / L
Angular velocity is related to frequency and period.
w = 2π f = 2π / T
We replace
2π / T = √ g / L
T = 2π √L / g
We will use the value of g = 9.8 m / s², the initial length of the pendulum, in general it is 1 m (L = 1m)
With this length the average time period is
T = 2π √1 / 9.8
T = 2.0 s
They indicate that the error accumulated in a day is 15 s, let's use a rule of proportions to find the error is a swing
t = 1 day (24h / 1day) (3600s / 1h) = 86400 s
e= Δt = 15 (2/86400) = 3.5 104 s
The time the clock measures is
T ’= To - e
T’= 2.0 -0.00035
T’= 1.99965 s
Let's look for the length of the pendulum to challenge time (t ’)
L’= T’² g / 4π²
L’= 1.99965 2 9.8 / 4π²
L ’= 0.9926 m
Therefore the amount that should adjust the length is
ΔL = L - L’
ΔL = 1.00 - 0.9926
ΔL = 0.0074 m
Answer:
First calculate the deceleration making use of the formulation: V(very last speed= U(initial speed) -a(acceleration) t(ime) so 10=20- 4a. unfavourable a as decelerating. making a the acceleration the challenge by using rearranging the elements 4a= 20-10 = 10 so a=10/4 making use of Newton's 2d regulation P(stress) = M (mass) x A (acceleration). so P = 800 x 10/4 = 8000 /4 = 2000 newtons
Explanation:
An LED is useful because when a current passes through it, it gives out light.