Answer:
0.24
Explanation:
Mass of ball= 12g=0.012Kg
height of ball= 2.5m
velocity of ball before falling= 3.2m/s
potential energy of the ball=mgh= 0.012*10*2.5=0.3J
kinetic energy of the ball=0.5*m
=0.5*0.012*3.2*3.2=0.6J
Loss in mechanical energy during the fall= potential energy- Kinetic energy= 0.3-0.06=0.24J
note: During the fall, the potential energy of the ball is converted to kinetic energy. the loss in energy is due to air resistance.
Velocity = distance /time
acceleration = velocity / time
Answer:

Explanation:
let A represent me and B represent my friend
A speed
=30 m/hr toward west
B speed
=40 m/hr toward south
after 1/2 hr
total distance cover by A =1/2 * 30 miles = 15 miles
total distance by B = 1/2*40 miles = 20 miles
now from figure


Differentiate above equation




Answer:
6.429 m/s^2.
Explanation:
Using equations of motion,
i. vf = vi + at
ii. vf^2 = vi^2 + 2a*S
iii. S = vi*t + 1/2 * (a*t^2)
Where,
vf = final velocity of the motion
vi = initial velocity of the motion
S = distance travelled
t = time taken to complete the motion
a = acceleration due to gravity
Given:
vi = 0m/s
vf = 45 m/s
t = 7 s
a = ?
Using the i. equation of motion,
vf = vi + at
45 = 0 + a*7
a = 45/7
= 6.429 m/s^2
B = 53°
Reason: Opposite angles
A = 37°
Reason: Sum of angels on a straight line = 180 so 180-90-53 = 37°
C = 90°
Reason: Right angles = 90°
D = 37°
Reason: Sum of angels on a straight line = 180 so 180-90-53 = 37°