Answer: Physical changes in nature could then be erosion in a mountain, the melting of snow, and a river freezing over from the cold. Since none of these changes affect the chemical composition of the mountain, the snow, or the river, they are physical changes.
Explanation:
Answer:
T
Explanation:
= magnitude of current in each wire = 2.0 A
= length of the side of the square = 4 cm = 0.04 m
= length of the diagonal of the square =
a =
(0.04) = 0.057 m
= magnitude of magnetic field by wires at A and C


T
= magnitude of magnetic field by wire at B


T
Net magnitude of the magnetic field at D is given as



T
Answer:
Explanation:
Let v is the launch speed of the plastic ball and the angle of projection is θ.
So, in horizontal direction
v Cosθ x t = 4.8 .... (1)
In th evertical direction
1.4 = v Sin θ x t - 0.5 gt² .... (2)
As , v Sin θ x t = 3.8 .... (3) , put in equation (2)
1.4 = 3.8 - 4.9 t²
t = 0.7 s
Put in (1) and (3)
v Cosθ x 0.7 = 4.8
v Cosθ = 6.86
and v Sinθ x 0.7 = 3.8
v Sinθ = 5.43
Now

v = 8.75 m/s