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Acceleration = (increase in velocity)/time taken = (45 - 25)/10 = (20)/10 = 2ms-2

Rough surface promotes friction. Therefore, roughness of conveyor belt prevents the load from slipping

Above are the V-t graphs for I Uniform acceleration II uniform retardation III Uniform velocity Thus the car has no acceleration between point F and G since that portion of the graph represents uniform velocity

Efficiency = (MA)/V.R x 100% = (load)/Effort x (1)/V.R = (800)/400 x (1)/6 x 100% = 33.3%

V\(^2 = U^2 - 2gs\) S = \(\frac{V^2 - U^2}{-2g} = \frac{O^2 - 30^2}{-2 \times 10}\) = 45m Height from ground = 50 + 45 = 95m Height from ground = 50 + 45 = 95m

A bod y is said to be in stable equilibrium if after a slight displacement, the body returns to its former position. Thus, position III, VI and XI represents position of stable equilibrium

V = f\lambda f = (v)/\lambda = (420)/42 = 10 HZ Period, T = (1)/F = (1)/10 = 0.1 secs

Length of the string L = y + x = 0.5m ∴ x = L - y = distance moved in the direction of force (which is the weight) when the body is released But cos 60o = y/0.5 ∴ y = 0.5cos60 = 0.5 x 1/2 = 0.25 ∴ x = l - y = 0.5 - 0.25 = 0.25m Work done = force x distance moved in the direction of force. = 0.1 x 0.25 = 0.025J

Since relative density = mass of substance mass of equal volume of water relative density bottle should be used to determine the mass of the substance, and mass of an equal volume of water by filling the bottle with the powder and water respectively and weighed with the beam balance.

The instrument used in measuring relative density is hydrometer

Density (D) = \(\frac{mass}{volume}\) \(\therefore Mass = Density \times volume\) = \(0.4 \times 20 = 8kg\) The initial volume = \(\frac{Mass}{\text{Initial density}}\) = \(\frac{8}{0.8} = 10m^{3}\)

Energy stored in a stretched wire (strain energy) = average force x extension = (1)/2 Fe = (1)/2 x 300 N (30.5 - 30.0) x 10-2 m = (300)/2 x 0.5 x 10-2 = 0.75J

Thrust = pressure x area = 100 pa x 3 m2 = 300 N

The low freezing point of alcohol, -115^\circc enable low temperatures to be measured. mercury freezes at 39^\circc, and cannot be used in countries like Russia where winter temperatures of -40^\circc are common

Infrared rays falling on the skin causes the skin causes the sensation of warmth. since the objects are hot, the correct option is informed.