Answer:
second one is correct that is right
Answer:
n = 1.4
Explanation:
Given,
R1 = 18 cm, R2 = -18 cm
From lens makers formula
1/f = (n - 1)(1/18 + 1/18) = (n-1)/9
f = 9/(n-1)
Power, P = 1/f ( in m) = (n-1)/0.09
Now, this lens is in with conjunction with a concave mirror which then can be thought of as to be in conjunction with another thin lens
Power of concave mirror = P' = 1/f ( in m) = 2/R = 2/0.18 = 1/0.09
Net power of the combination = 2P + P' = 2(n-1)/0.09 + 1/0.09 = 1/0.05
n = 1.4
Answer:
10.4 m/s
Explanation:
The problem can be solved by using the following SUVAT equation:
where
v is the final velocity
u is the initial velocity
a is the acceleration
t is the time
For the diver in the problem, we have:
is the initial velocity (positive because it is upward)
is the acceleration of gravity (negative because it is downward)
By substituting t = 1.7 s, we find the velocity when the diver reaches the water:
And the negative sign means that the direction is downward: so, the speed is 10.4 m/s.
Answer:
F=m x a
(F is force ,M is mass and A is acceleration)
in thisncase the Mass is given but we need to find ou the acceleration
Formula for acceleration-
a=(v - u)/t
(v is final velocity , u is initiatal velocity and t is time)
a = (0 - 80)/4
a= -80/4
a= -20
By substituting the values-
F= m x a
F= 1500 x -20
F=-30000N
Thus the force acted is -30000N
hope this helps
Weight equals mass times gravitational acceleration=400N, so mass=400/9.8=41kg approx.
