Let u = the speed of the car at the instant when braking begins.
The braking distance is s = 62.3 m, the acceleration is a = -5.9 m/s², and the braking duration is t = 4.15 s.
Use the formula s = ut + (1/2)at² to obtain
(u m/s)*(4.15 s) + 0.5*(-5.9 m/s²)*(4.5 s)² = (62.3 m)
4.15u = 62.3 + 50.8064 = 113.1064
u = 27.2546 m/s
Let v m/s be the speed with which the car strikes the tree.
Then
v = 27.2546 - 5.9*4.15
= 2.7696 m/s
Answer: 2.77 m/s (nearest hundredth)
Answer:
the speed of the waves is 150 cm/s
Explanation:
Given;
frequency of the wave, f = 10 Hz = 10
distance between 4 nodes, L = 15.0 cm
The wavelength (λ) of the wave is calculated as follows;
Node to Node = λ/2
L = 2(Node to Node) = (4 Nodes) = 2 (λ/2) = λ
Thus, λ = L = 15.0 cm
The speed (v) of the wave is calculated as follows;
v = fλ
v = 10 Hz x 15.0 cm
v = 150 cm/s
Therefore, the speed of the waves is 150 cm/s
Answer:
(d) not enough info
Explanation:
because it doesn't specify where the strings are attached
if it was the two ends of the rod then T1 would be equal to T2
Answer:
c) 11.9 yr
Explanation:
The orbital period is proportional to r^(3/2) and does not depend on the satellite's mass. Any object at Jupiter position will have the same orbital period regardless of mass.
By keppler's law we know that
T^2= r^3
T= orbital time period
r= mean distance of the planet from the Sun.
clearly, The orbital period does not depend on the satellite's mass
there, the correct answer will be c= 11.9 yr.
weight = mg acts
downwards <span>
normal force = N acts upwards.
and force F acts at an angle θ below the horizontal.
(Let us assume that the woman pushes from the left, so F is
acted towards the right, which is below the horizontal)
so that, Frictional force, f=us*N acts towards the left
Now we balance the forces along x and y directions:
y direction: N = mg + F sinΘ
x direction: us * N = F cosΘ
We let the value of µs be equal to a value such that any F
will not be able to move the crate. Then, if we increase F by an amount F',
then the force pushing the crate towards the right also increases by F' cosΘ. Additionally,
the frictional force f must raise by exactly this amount.
Since f can’t exceed us*N, so the normal force must increase
by F' cosΘ/us.
Also, from the y direction equation, the normal force exceeds
by F' sin Θ.
<span>These two values must be the same, therefore:
<span>us = cot θ</span></span></span>
