Answer:
Friction produces unnecessary heat leading to the wastage of energy. The force of friction acts in the opposite direction of motion, so friction slows down the motion of moving objects. Forest fires are caused due to the friction between tree branches. However, friction can also cause problems in a car. Friction between moving engine parts increases their temperature and causes the parts to wear down. Friction can be both harmful and helpful, so it may be necessary to decrease or increase friction.
Answer:
correct option is d) 7.0 x 10^-7 N
Explanation:
given data
distance = 175 picometers = 1.75 × 
m
to find out
electrical force
solution
we know atomic no of uranium is 92
and charge on electron is = 1.6 × 
C
and electrical force is express as
electrical force = 
.............1
put here value we get
electrical force = 
electrical force = 6.921 × 
N
so correct option is d) 7.0 x 10^-7 N
Answer:
17.55 m/s²
Explanation:
Parameters given:
Mass of Krypton, M = 7.6 * 10^23 kg
Radius, R = 1.7 * 10^6 m
Gravitational constant, G = 6.6726 * 10^(-11) Nm²/kg²
Acceleration due to gravity of planet of mass M is given as:
g = GM/R²
Since the object is close to the surface of Krypton, we can say that the distance from the Centre of Krypton is the radius of the planet Krypton.
Therefore,
g = (6.6726 * 10^(-11) * 7.6 * 10^23)/(1.7 * 10^6)²
g = 17.55 m/s²
