Friction can be increased by :
Making the surfaces rough
Using dry surfaces
Increasing the weight
All of the above
Pressure depends an ............. and ............... . Which information completes the given statement?
Mass, Force
Mass, Volume
Force, Area
Force, Volume
It is better to use a sharp tripped nail than a blunt nail because
The tip with the smallest area will produce a higher pressure when a small force is applied
A sharp tipped nail needs a larger force to drive it into the wooden surface
The sharp tip saves cost as less raw materials are required to make such nails
The sharp tip has a spiralling effect when the nail is hit on the head
The average atmospheric pressure at sea level is 760 mm Hg. If the relative density of mercury is 13.6.Determine the vertical length of a water column at sea level ?
0.76 m
10.336 m
101396 m
10336 m
Which of the following is NOT true ?
A sharp knife can easily cut due to its small cutting surface
It is easier to walk in sand than on road
A battle tank can move easily on soft ground because its tracks have bigger surface
The pressure exerted by a needle is much more than the foot of an elephant
Sonia wants to hit some pins in a bowling game as shown in figure. To do so, where she whould apply a force on the ball.
I
II
III
IV
Pressure varies with force (F) as (providing area is same)
F
F2
Sohan is unable to lift a box off the ground. The force that make it difficult to do so is
i) The weight of the box
ii) The weight of the sohan
iii) Gravity
iv) Friction
i and ii only
i and iii only
ii and iii only
iii and iv only
1 kg wt is equal to
1kg
1 N
9.8 kg
9.8 N
One arm of a glass U-tube is open to the atmosphere, whereas the other vertical arm is connected to a gas supply. The difference in levels of mercury (density = 13.6 g cm-3) between the vertical arms of the U-tube manometer is h = 3 cm. If the atmospheric pressure is 760 mm Hg and the gravitational acceleration is 9.8 m s-2, Calculate the pressure of the gas ?
1.053 × 106dynes cm-2
1.074 × 104dynes cm-2
3.998 × 104dynes cm-2
1.017 × 107dynes cm-2
