Answer: 1.95s
Explanation:
Given
ma = 290 cos 34.9 - fk
fk = 290 cos 34.9 - ma
fn = mg + 400 sin Φ
fn = 290 + 400 sin 34.9
fn = 290 + 228.9
fn = 518.9
fk = fn * uk
uk = 0.57
290 cos 34.9 - ma = 518.9 * 0.57
290 cos 34.9 - ma = 295.8
290 cos 34.9 - 295.8 = ma
ma = -58
m = 290/10 = 29
a = 58/29
a = 2
Using equation of motion
S = ut + .5at²
3.8 = 0 + .5*2*t²
3.8 = t²
t = 1.95s
Answer:
C. 720 N up
Explanation:
Newton's third law states that:
"When an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A"
In this situation, we can imagine the man to be object A and the bench as object B. The force exerted by the man on the bench is:
720 N, down
So according to Newton's third law, the bench must exert an equal and opposite force on the man. Therefore, the force exerted by the bench must be
720 N, up
It takes 7.0s for a piece of wood to be falling from a tall building in the velocity of 68.6 m/s
<u>Explanation:</u>
v = u + at
68.6 ms^-1 = 0 ms^-1 + (9.8 ms^-2 x t)
t = 68.6 ms^-1 / 9.8 ms^-2
t = 7.0s
It takes 7.0s for a piece of wood to be falling from a tall building in the velocity of 68.6 m/s
Explanation:
It is given that,
Radius of curvature of the mirror, R = 1.54 cm
(a) We have to find the focal length of the mirror. The relationship between the focal length and the radius of curvature is given by :

f = focal length of the mirror

f = 0.77 cm
(b) The power of mirror is given by the reciprocal of focal length i.e.
Power, 
P = 1.29 diopters
Hence, this is the required solution.
yes, just like human skin. The bigger you grown the more your skin stretches, I a fish is bigger their skin will stretch leading to broad stripes.