F=ma
8480=26.5m
m=8480/26.5
m=320
The mass of the cart is 320kg.
Answer:

Explanation:
From frequency of oscillation

Initially with the suspended string, the above equation is correct for the relation, hence

where k is force constant and m is the mass
When the spring is cut into half, by physics, the force constant will be doubled as they are inversely proportional

Employing f2/ f1, we have

Answer:
An engine with an electronic fuel injection system has high fuel pressure at idle because of high manifold vacuum. (option D)
Explanation:
Electronic fuel injection (EFI) system replaced carburetors back in the mid-1980s as the preferred method of supplying air and fuel to engines. The basic difference is that a carburetor uses intake vacuum and a pressure drop in the venturi, to siphon fuel from the carburetor fuel bowl into the engine. Whereas fuel injection system uses pressure to spray fuel directly into the engine.
However, under light load or at idle, a relatively high vacuum exists in the intake manifold. This means less fuel pressure is needed to spray a given volume of fuel through the injector. Under heavy load, engine vacuum drops to near zero.
Therefore, An engine with an electronic fuel injection system has high fuel pressure at idle because of high manifold vacuum.
X=ut+0.5at²
1000 = 63.3u + 0.5 * 0.0323 * 63.3²
u = (1000 - 0.1615*63.3²)/63.3
u = 5.57 m/s
i don't even know if this is correct